# Ou4

> double star in the constellation Cepheus

**Wikidata**: [Q87016282](https://www.wikidata.org/wiki/Q87016282)  
**Source**: https://4ort.xyz/entity/q87016282


## References

1. SIMBAD
2. [Source](https://apod.nasa.gov/apod/astropix.html)
3. The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright southern stars
4. Washington Double Star Catalog
5. Catalog of Galactic OB Stars
6. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
7. Validation of the new Hipparcos reduction
8. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system
9. The interstellar Ca II distance scale
10. The IACOB project. III. New observational clues to understand macroturbulent broadening in massive O- and B-type stars